Responsiveness

That is great news for the bugs you found, but there is more to it than that.

If the developers had been busy at the time and couldn't work on it immediately, are you sure
that they wouldn't have lost your report?

When the developers are preparing a release, do they know what problems are fixed?  Do they
know what problems haven't been fixed?

When a new issue is reported, do the developers have a way of deciding how important it is
relative to the other open issues?

These sorts of things are very useful when deciding what problems to fix or making a release.